Deflecting plate for cathode ray tubes



Dec. 18, 1945. R. E. RUTHERFORD 2,391,273

DEFLECTING PLATES FOR CATHODE RAY TUBES Filed May 29, 1942 HILHIIIIIIII IIIIIIlll mmi g I By H" H T TOR/V5 Y Patented Dec. 18, 1945 DEFLECTIN G PLATE FOR CATHODE RAY TUBES Robert E. Rutherford, Rutherford, N. J., assignor to Allen B. Du Mont Laboratories, Inc., Passaic, N. .L, a corporation of Delaware Application May 29,1942, Serial No. 444,962

2 Claims.

This invention relates to deflecting plates for cathode ray tubes. One ofthe objects of the invention is to produce such plates so that there are no rough or irregular edges thereon that would tend to distort the electron beam. Another object is to construct and mount the. plates in such a way that they maintain their exact shape and relative positions with respect to each other and are free from vibration. Another object is to make the plates very stiff and rigid without interfering with the usual functioning of the same. Other objects will be apparent as the description proceeds.

Heretofore, deflecting plates for cathode ray tubes have been made of thin sheets cut from larger sheets. The result has often been that when these plates were installed they were warped or bent or became displaced with respect to each other, thus resulting in lack of symmetry. Besides, the cut edges were often left rough or with small projections thereon which caused irregularities in the electrostatic field when the plates were energized.

By the present invention deflection plates are made that are free .from burrs or rough or irregular spots along the edges thereof, the diverging angle between the plates as well as the distance between the plates where they are installed is accurately controlled and retained, and the plates themselves are made very rigid, thus preventing unwanted bending or distortion thereof.

The invention will be understood from the deand I2 in place. Mica discs l4 and ii are provided with holes having eyelets therein so that the rods I, 2, 3 and 4 can pass therethrough and support these discs at fixed distances apart.

A pair of deflecting plates [6 and I1 and another pair of deflecting plates i8 and I9 at right angles to the first pair are mounted upon the rods or supports I, 2, 3 and 4, and upon the auxiliary short supports 20, 2|, 22 and 23, the auxiliary supports being attached to the discs I4 and by eyelets in the usual way.

One of the deflecting plates I1 is shown in Figs. 4 and 5 on an enlarged scale, the four deflecting plates being made alike. Each of the deflecting plates consists of a flat sheet, and the two plates of each pair are so mounted that they diverge scription in connection with the accompanying drawing, in which:

Fig. l is a plan view of an illustrative embodi- 4 indicate metal rods of the usual sort that are to be electrically connected through a press (not shown) and secure or hold in place deflecting electrical connection thereto.

Insulating tubes 5 and 6 of ceramic or other suitable material are mounted on the rods I and 2. Metal straps I, 3 and 9 are attached to the ceramic tubes 8 and 8 to keep the grid l0 and anodes ll plates for a cathode ray tube, and also to make from each other in the direction of the cathode ray beam that passes between them.

The upper and lower edge of each plate is bent inwardly as shown at 25 and 26, thus leaving rounded corners 21 and 28 that are smooth and free from burrs. The side of each plate I! is bent at right angles to form long flanges 29 and 30, thus producing rounded edges 31 and 32 that are free from burrs. The flanges 29 and 30 have grooves 33' and 34 formed therein to receive the metal rods l and 20 to which they are spot welded; and similarly for the three other plates and corresponding rods.

In view of the fact that the upper and lower edges of the plate I! are provided with the flanges 25 and 26, the danger of this plate being accidentally cupped or curved transversely is obviated, and the flanges 29 and 30 prevent cupping or curvature of the plate in the other direction so that the surfaces of the plates that face each other are maintained straight, and in addition the supports for the plates keep them spaced a fixed distance apart as well as maintaining the angle of slope between the plates from varying.

What is claimed is:

1. A deflecting plate for a cathode ray tube having edges thereof bent at an angle thereto,. said edges having grooves therein for receiving mounting members.

2. A deflecting plate for a cathode ray tube' having edges thereof bent at an angle thereto,

ROBERT E. RUTHERFORD. 

